Blowout preventer



J g 2, 19 F. .1. HINDERLITER 2,234,859

I BLOWOUT PREVENTER Filed Feb. 27; 1940 Patented June 2, 1942 r i j OFFICE "BLoWoU'r PREVENTER v FrankJ. Hinderliter, Tulsa, Okla. Application February 27, 1940, SerialNo. 321,017 g 1 Claim. This invention relates to blowout preventers for easing heads; of the general type shown in my Reissue Patent No. 19,047, entitled Casing head with blowout preventer, and has, as one of its principal objects, the provision of a relatively 1y effective blowout preventer. I

Another object of this invention is to provide a blowout preventer which can be readily lubricated for the easy passage of well tubing through it l I l simple and inexpensive but nevertheless extreme- Another object of this invention is the pro vision of'a blowout preventer having a one-piece rubber orsealing member constructed and arranged to beheld in tight sealing engagement both with the member in which it is mounted and with the tubing passing through it by means of the pressure within the casing head.

According to the principal features of this invention, there is provided a blowout preventer rubber having a tapered portion extending down into engagement with the well tube and provided on its upper surface with longitudinal grooves adapted to cooperate with couplings of the tube for feeding lubricant down along the .inner surface of the blowout preventer rubber.

Another feature of the invention is the forming of the rubber in asingle piece with a downwardly extending lip engaging the inner surface of the member in which the rubber is mounted.

Other objects andfeatures of this invention will more fullyvappear from the following detailed description taken in connection with the accompanying drawing which illustrates one of the preferred embodiments thereof, and in which:

Figure 1 is a vertical section through a casing head hookup including one embodiment of the invention;

Figure 2 is a vertical section of the blowout preventer shown in Figure 1, the remainder of thecasing head being omitted,,and showing the passage of a tube coupling throughthe blowout preventer; and j" Figure 3 is a plan view of the blowout preventer shown in Figures 1 and 2, the tube passing through the blowout preventer being shown in section.

As shown in the drawing:

The preferred form of the invention formsa part of a casing head hookup which comprises a forged steel casing head It) adapted to be screwed onto the upper. end of a well casing II in the usual manner. The casing head l0 isprovided with a pair of side outlets l2 for receiving pipes l3 through which oil, gas or other fluids may be removed from or introduced into the easing II. The upper end of the casing head I0 is counterbored, the counterbore l4 terminating above the side outlets l2 in a sloping shoulder IS.

A forged steel adapter I6 is screwed onto the upper end of the casing head I 0 and is formed with a counterbore I! which has the same diameter and isaligned with the counterbore 14 in the upper end of the casing head. A gasket I8 is setinto a groove in the shoulder at the lower end ofthe counterbore ll in the adapter 16 and forms a tight seal between the adapter and the casing headwhen the adapter is screwed down tight onto the casing head. i

The upper end of the adapter I6 is formed with a counterbore I9 having the same "diameter as the counterbore I4 in the upper end of the casing head and terminating in a sloping shoulder 20 similar to and at the same angle as the sloping shoulder l5 at the bottom of the casing head counterbore I4.

The upper adapter counterbore l9 contains a bushing 2| seated upon the shoulder 20 and having a steep rconical surface 22 upon which are seated a plurality of slips 23 adapted to grip a well tube24 which extends down through the casing head hookup. The slips 23 are provided with teeth on their inner surfaces and function in the usual manner, being wedged 'against the sides of the tube24 by the actionof theconical -or tapered surface 22 in the bushing 2i The upper end of the adapter It contains an auxiliary packing mechanism comprisinga lower steel ring 25, an auxiliary pack rubber 2E and an upper steel ring 21 resting in superposed relation on topof the bushing 2|. These parts are held iii-place by a steel cap 23 which screws onto the top of the adapter [6 and forms a means for compressing the rubber 26 and forcing it tightly against the Well tube 24.

The blowout preventer 293il3l is located in the counterbores l4 and I! in the top. of the casing head Ill and the bottom of the adapter it and comprises a sleeve 29, a rubber 30 mounted in the sleeve, and a retaining ring 3! which holds the'rubber 30in the sleeve 29. The lower end of. the blowout preventer sleeve 29 is provided with a" gasket 32 adaptedto bear against the sloping shoulder l5 at the bottom of the counterbore M in the casing head and to? form a pressure tight joint at that point. Sufficientpressure for making the joint tight is provided by screwing the adapter I6 down upon the upper end of theblowout preventer sleeve 29.

The inside of the blowout preventer sleeve 29 is machined to provide a collar. 33 with a, deeply undercut upper surface. This surface forms one sideof an annular groove, the other side of the groove being the inner surface of the sleeve 29 above the collar 33., The collar 33 supports the base or anchor portion 34 of the blowout preventer rubber 30, this portion 34 being seated against the inside of the sleeve 29 and having a lip 35 projecting down into the groove'formed by the collar 33. The retaining ring 3| is screwed.

screwing it.

Besides the anchor portion 34 and the lip 35,

i the blowout preventer rubber 30 also comprises an intermediate tapered connecting portion 31 and a lower or cuff portion 38 adapted to fit tightly around the well tubing 24. V The connecting portion 31 is in the form of a conical wall 7 attached at its larger and upper end to the base portion 34 of the rubber and carrying the cuff or sealing portion 38 at its lower end. The function of the connecting portion 31 is to support the cuff 38 against vertical movement while allowing it to expand or contract as required in order to maintain its tight sealing engagement with the well tube 24. This action is illustrated in Figure 2 which shows a coupling 39 on the well tubing 24 passing through the blowout preventer. As may be seen from this figure, the base portion 34 of the rubber is undisturbed while the lower part of the connecting portion 31 and the cuff 38 are expanded enough to permit the passage of the coupling 39.

An important feature of the present invention is the provision of longitudinal grooves 40 on the upper surface of the connecting portion 31 of the rubber. When tubing 24 is being run or lowered through the blowout preventer, the space within the blowout preventer around the tubing 24 is filled or partially filled with a suitable lubricant, such as the material known as aquagel, which serves to lessen the friction between the tubing 24 and the blowout preventer rubber 30. As each coupling 39 on the tubing 24 passes down through the blowout preventer rubber, its lower edge traps a small amount of the lubricant and carries it down through the rubber, spreading it over the inner surface of the rubber in doing so and thus providing lubricant for the next length of tubing. The grooves 4|] serve to aid and regulate this action and insure that the proper amount of lubricant will be carried through by each coupling.

The casing head hookup in which the blowout preventer has been illustrated is extremely flexible in the manner in which it may be used. If the utmost security against blowouts is desired, a second adapter similar to the adapter 16 can be secured on top of the first adapter and a second blowout preventer placed in the chamber formed by the two adapters while the adapter bushing 2|, slips 23, and the auxiliary packing mechanism 25-46-21, and steel cap 28 are placed in and on the upper end of the upper adapter. This arrangement is made possible by the fact that the counterbore 19 in the upper end of the adapter l6 has the same length and diameter as the counterbore [4 in the casing head ii] and the sloping shoulder 20 at the bottom of the adapter counterbore I9 is at the same angle as the sloping shoulder 15 at the bottom of the casing head counterbore l4.

When there is no longer any danger of a blowout of the well upon which the blowout preventer has been used, the adapter l6 and the blowout preventer 29303I may be removed from the casing head 10 and the adapter bushing 2|, the slips 23, and the auxiliary packing mechanism 25-2621 may be placed in the counterbore I4 in the upper end of the casing head and retained in place by the steel cap 28 removed from the upper end of the adapter I6. If desired, other types 'of tubing hangers, such as those into which the upper end of the well tubing is adapted to be screwed, can be used in the casing head 10 after the blowout preventer 29-30--3l adapter [6 have been removed.

The blowout preventer 29303I may also be used in an' inverted position as a sealing means around the well tubing in wells which are producing under vacuum. When used for this purpose, either the casing head I0 is machined to receive the blowout preventer in an inverted position or, preferably, the blowout preventer sleeve 29 is modified either to hold the rubber 30 in an inverted position or to fit into the casing head in an inverted position itself.

From the above, it will be seen that I have provided a blowout preventer and a casing head assembly which are extremelyfiexible in use and which are simple and efficient in their construction.

It will, of course, be understood that various details of construction may be varied through a wide range without departing from the principles of this invention, and it is, therefore, not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claim.

I claim as my invention:

In combination, a well head, and a blowout preventer assembly disposed in said Well head comprising a cylindrical rigid sleeve having at its lower end an inwardly inclined seating surface adapted for supporting and abutting cooperation with a seat in the well head, and provided on its interior with an annular shoulder, an annular rubber blowout preventer disposed in said sleeve having an enlarged portion at its upper end seated on said sleeve shoulder, said shoulder being upwardly and inwardly inclined and said rubber preventer having an inclined lip tightly fitted behind said shoulder whereby said rubber preventer is interlocked with said sleeve, said preventer having a downwardly depending reduced cuff-like portion adapted to embrace sealingly pipe lowered through the preventer, said reduced portion being spaced from said sleeve to provide an annular space in which fluid under pressure may enter the preventer between said rigid sleeve and said reduced portion, said sleeve and the enlarged upper portion of said preventer being substantially concentric with said sleeve circumferentially encompassing said enlarged upper portion to restrain said portion against radially outward movement, and means for holding and compressing said annular portion against and in sealed cooperation with said shoulder, said inclined surface having gasket sealing means adapted to establish a seal between the preventer and well head and said head having means for pressing said preventer downwardly to hold said gasket means in sealing position.

' FRANK J. HINDERLITER.

and the 

